1. Field of the Invention
The present invention relates to an operation indicating device for an electromagnetic relay and in particular to an operation indicating device for an electromagnetic relay wherein the display configuration is simplified to substantially widen the space within the case cover and make it effectively usable.
2. Description of the Related Art
Some conventional electromagnetic relays have operation indicating devices for indicating the open/close states of the relays. One example of their configurations is shown in FIGS. 8A and 8B. FIG. 8A is the side view of a longitudinal section of a conventional electromagnetic relay and FIG. 8B is the front view of a longitudinal section of the electromagnetic relay. In this prior art example, a slender operation indicating member 9 made of an elastic material is erectly installed on a base 2 of the electromagnetic relay 1. A piece 9a formed by cutting and raising one portion of a middle part in the operation indicating member 9 is linked to an insulation plate 5a attached to an armature 5. When the contact of the electromagnetic relay 1 is closed, i.e., when the armature 5 is attracted to a core 3a of an electromagnetic coil 3, the operation indicating member 9 is drawn to the electromagnetic coil 3 so that an indicating portion 9b formed by bending the upper end of the operation indicating member 9 in a reversed L form may be confronted by an indication window 8a formed in a case cover 8. As a result, the operative state of the electromagnetic relay 1 is indicated through the window 8a. Reference numerals 4, 6 and 7 denote a yoke, a movable contact plate and a return spring, respectively.
In the above described operation indicating device of the electromagnetic relay 1, the operation indicating member 9 is so disposed as to be opposed to the armature 5. The space near the contact is thus reduced. As a result, it is difficult to obtain a sufficient insulation distance, and insulation is deteriorated by the deposition of carbon caused by arc when the contact is opened or closed. The problem of limitation in the number of contact poles is also incurred.